Classification of growth behaviour for copper on various substrates with in-situ scanning probe microscopy

Abstract

In-situ scanning probe microscopy has been used to directly examine the deposition of copper on gold, polypyrrole and gold substrates which have been precovered with a multilayer copper film. The growth of the copper deposits, from electrolytes with and without additives, have been classified for these different substrates in accordance with Bauer [1] as either: (A) the Stranski-Krastanov mechanism involving the deposition of one or more layers followed by the formation of three-dimensional islands; (B) Frank-van der Merwe layer-by-layer growth of either individual monolayers (B 1); or multilayer films (B 2); or (C) the Volmer-Weber mechanism involving the formation of bulk islands directly on-top of the substrate. We show that the growth behaviour can be rationalised in terms of simple thermodynamic models which take into account, the strength of the deposit-substrate interaction and the crystallographic misfit between the deposit and the underlying substrate surface.